Currently in the manufacture of paint rollers, strips of pile fabric are used which are wound around a plastic or cardboard tube or core. More specifically, among the devices currently employed is a type of machine illustrated in Spanish Utility Model No. 293.980, which includes a rotating cylinder over which the plastic or cardboard tube is mounted, and onto which a strip of pile fabric is applied through a guide oriented obliquely and situated on and carried by a carriage which is mounted in fixed fashion over a sliding apparatus. The bonding of the plastic tube and strip of pile fabric is accomplished either by the application of adhesive material or by the use of a plastic tube which, when heated by means of gas burners, bonds to the strip of pile fabric, thereby forming a single body.
In the first case, i.e., where conventional adhesive is used as the means of bonding between the tube and strip of pile fabric, the manufacture of paint rollers presents significant problems, all resulting from the difficulty of applying the adhesive uniformly, plus the fact that very specific adhesives must be used to produce the bond between the tube and the strip of pile fabric so that, when the rollers are used, these adhesives do not separate due to the solvents contained in the paint and in the fluids used to clean the roller.
These problems considerably increase the cost of manufacturing paint rollers because the cost of the adhesives and the time needed for the adhesives to harden.
The second system mentioned above, though a significant advance in the art over what had been earlier used, does present certain problems, all resulting from the increased safety costs required by installations that use gas as a fuel source. Further, the heating of the plastic tube can produce undesirable products of combustion and high noise, both effects being potentially harmful for the operators and expensive to eliminate; all of this therefore has the result of raising the cost of the final product.